The semiconductor industry has recently experienced technological advances that have permitted dramatic increases in integrated circuit density and complexity, and equally dramatic decreases in power consumption and package sizes. Present semiconductor technology now permits single-die microprocessors with many millions of transistors, operating at speeds of hundreds of millions of instructions per second to be packaged in relatively small, air-cooled semiconductor device packages.
A by-product of such high-density and high functionality is an increased demand for products employing these microprocessors and devices for use in numerous applications. As the use of these devices has become more prevalent, the demand for faster operation and better reliability has increased. Such devices often require manufacturing processes that are highly complex and expensive.
As manufacturing processes for semiconductor devices and integrated circuits increase in difficulty, methods for testing and debugging these devices become increasingly important. Not only is it important to ensure that individual dies are functional, it is also important to ensure that batches of dies perform consistently. In addition, the ability to detect a defective manufacturing process early is helpful for reducing the number of defective devices manufactured.
The analysis of semiconductor dies often involves defect detection and identification. It is desirable to have the ability to determine the cause and location of defects in dies for various purposes, such as to improve upon the design or manufacture of the dies. However, analysis of semiconductor dies is inhibited by difficulties associated with locating and obtaining images of the defects. At times, locating a defect involves removing portions of the die to expose the defect. Accessing defects in the die can sometimes be destructive, and can inhibit the ability to adequately image a defect. In some instances, the defect itself may be obscured or removed before an image can be obtained. For these and other reasons, the detection, location and identification of defects has been challenging.